Various embodiments of this disclosure relate to location-based services and, more particularly, to offering privacy for continuous location-based services.
Location-based services (LBSs) are services offered based on the specific locations of mobile users. Continuous LBSs are services that require continuous or repeated updates of a user's location in order for the services to work properly. For example, navigation is a continuous LBS, as it requires monitoring the user's location to provide a route from the current location to a chosen destination. An ongoing issue with LBSs is the lack of privacy. When a user requests a LBS, the service provider must generally be allowed to monitor the user's continuing location changes, which may be more information about the user than the user desires to provide.
In a basic implementation of a LBS, providing no privacy, the user's device communicates directly with a LBS provider to receive a LBS. Privacy can be offered in LBS based on either of two communication models. In a distributed setting, the user's device can communicate with a number of peers, choosing a peer at random at each given time to communicate with the LBS provider on the user's behalf. In a centralized setting, the user's device can communicate directly with a trusted server. The trusted server transforms the user's location and communicates the transformed location to the LBS provider. When responses are received by the LBS provider, the trusted server then transmits to the user's device only the data that is related to the user's actual location. Although this last option is an improvement over the other two, all these mechanisms have drawbacks with respect to privacy.